Ratios & Unit Rates

Front

What is a ratio?

Back

A ratio is a comparison of two quantities that shows the relative size of one quantity to another, often expressed as 'a to b' or a:b.

Front

What is a unit rate?

Back

A unit rate is a ratio that compares a quantity to one unit of another quantity, often expressed as 'x per 1 unit'.

Front

How do you calculate a unit rate from a total quantity and time?

Back

To calculate a unit rate, divide the total quantity by the total time. For example, if a store sees 120 customers in 8 hours, the unit rate is 120 customers ÷ 8 hours = 15 customers per hour.

Front

What is the unit rate in hours per dollar if someone earns $20 in 4 hours?

Back

To find the unit rate in hours per dollar, divide the total hours by the total dollars earned. In this case, 4 hours ÷ 20 dollars = 0.2 hours per dollar.

Front

How do you compare unit rates to determine who is faster?

Back

To compare unit rates for speed, calculate the unit rate (laps per minute) for each person and compare the values. The higher the unit rate, the faster the person.

Front

What is the formula to find gas mileage per gallon?

Back

Gas mileage per gallon is calculated by dividing the total miles driven by the total gallons of gas used. For example, if a car drives 144 miles on 4 gallons, the mileage is 144 miles ÷ 4 gallons = 36 miles per gallon.

Front

What does it mean if two ratios are equivalent?

Back

Two ratios are equivalent if they represent the same relationship between quantities, meaning they simplify to the same fraction.

Front

How can you determine if two ratios are equivalent using cross-multiplication?

Back

To determine if two ratios a:b and c:d are equivalent, cross-multiply: if a*d = b*c, then the ratios are equivalent.

Front

What is the unit rate for 15 dollars for 5 pairs of socks?

Back

To find the unit rate, divide the total cost by the number of pairs: 15 dollars ÷ 5 pairs = 3 dollars per pair.

Front

What is the unit rate for 25 dollars for 10 pairs of socks?

Back

To find the unit rate, divide the total cost by the number of pairs: 25 dollars ÷ 10 pairs = 2.5 dollars per pair.